Posted
by
samzenpus
on Wednesday November 09, 2011 @10:55PM
from the fire-it-up dept.

tetrahedrassface writes "NASA successfully test fired the J-2X engine Wednesday for 500 seconds at Stennis Space Center. The J2-X is derived from the J2 engine from the Apollo Era, and will power the upper stage of the SLS. From the article: 'We have 500 seconds of good data, and the first look is that everything went great. The J-2X engine team and the SLS program as a whole are extremely happy that we accomplished a good, safe and successful test today,' said Mike Kynard, Space Launch System Engines Element Manager at NASA's Marshall Space Flight Center in Huntsville, Ala. 'This engine test firing gives us critical data to move forward in the engine's development.'"

so they rebuilt 1960's technology and it worked...so lets find those old engineers who designed stuff that actually worked and pat them on the back.

If I remember correctly, the J-2X is a substantially improved version of the engine with a few hundred changes over the original J-2, but, yeah, this story would be more interesting if SLS was ever going to fly.

to bring the project in significantly under budget, then yes, the thing might actually fly someday. Otherwise, it's just another waste of money. In the last 10 years, SpaceX has built up an entire booster family (and attendant infrastructure) for less money than SLS is projected to cost per launch.

In a few more years, when SpaceX is flying astronauts to the ISS, and has an even bigger booster than SLS on the drawing board, then SLS will finally die a long overdue death. It's a shame to waste all that money, but when Congress is owned by corporate interests there's no easy way around that.

Hey, that's my dad you're talking about! Dad worked on what was then called the J-2X (a different program from the current J-2X) during the Saturn program, and is still working for NASA on the new vehicles.

Well, the 747 first flew in 1969 and it still looks the same today. Some things don't change because they can't, they're already pretty much at the limit of what's possible. Too often people think that because we've gotten better at storing and flipping bits, which requires almost no energy at all, that this means everything else has gotten better too.

So much for the space commute to the orbital ball bearing factory and the weekends on Mars, eh?

Yes, there is always the benevolent dictator path - though you get the good (like a string of economic growth) with the bad (almost constant rioting and general human rights abuses). Though China is far more complicated than a simple dictatorship - there is actually quite a bit of conflict behind the scenes - it's just that at the end of the day there is only one party.

In terms of aviation, there have been substantial improvements in many related technologies that can be applied to commercial aircraft since the original 747 made its first test flight. Indeed the 747 itself has changed many times and what is coming off the production line today in some ways doesn't even resemble the aircraft that was originally produced.

To pull this argument completely to pieces, Boeing even has plans to replace the 747 [wikipedia.org] due to some of the changes in aviation technology that essentially require a complete clean-sheet redesign of the aircraft. There have been improvements in the technology, and sometimes when you have a wide swath of technological improvements it can be a good time to look at something new.

This said, as was the case for the 747 and the original J-2 engine, what is being expected out of these devices is precisely what was wanted when they were original built in the 1960's. It shouldn't be surprising that something very similar is able to perform the very same task. I use a toaster to warm my bread with a device that looks very similar to what my grandmother had when I was a little child.

Actually the risk is more one of sounding like you were too lazy to do even the most basic google search and reading about the J-2X.

There were multiple reasons why the J-2 was selected as the base starting point for a secondary stage engine, mainly the existing performance parameters from the original design and the cost savings gained by not starting from scratch.

However, the J-2X actually has a significant amount of R&D that have gone into improvements w

Steam, actually, as vast quantities of the Pearl River are turned into vapor. (Plus the relatively small amount of water vapor made by the combustion of liquid hydrogen.) If you plan to fire a rocket against a fixed point for over eight minutes, you'd better have one hell of a good cooling (and noise-damping) system. Fortunately for them, they do.

Yes, I get the joke, but you also missed the point and were technically inaccurate all at the same time. Water vapor is just another way of describing steam, but with its partial pressure being much lower due to the fact that it hasn't condensed yet. On the Earth, water vapor is almost always a significant component in the air and is measured as "relative humidity".... also colorless and odorless like steam.

I doubt it. I'd expect the Star Trek TNG episode "Relic" would be nearly a documentary on this sort of thing. Old-school engineers worked in a different environment with simpler machines and tools. You'd get a few cases where modern engineers are less willing to push the envelope than the old-school engineers, and a lot of cases where the old school engineer is just in the way, and his "let me tinker with it" attitude causes problems for the complex highly automated modern systems.

Bring forward through time those same engineers with all of today's advancements and they'll stomp all over today's talent.

Bullshit. Give any group of talented engineers a sense of motivation, a nearly unlimited budget, and clear, specific goals, and they can do wonders.

The Manhattan project reached approximately 1% of all federal spending in its peak year. It had one aim: build an atom bomb. It had one main motivation: keep the bad guys (who had launched a sneak attack on us already) from taking over the world.

The Apollo program touched a massive 2.2% of all federal outlays in its peak year. It had three specifications: Man, Moon, Decade. It had one main motivation: keep the bad guys (who had put a satellite in orbit, and a man in space, first) from taking over the world. (Figuratively or literally, depending on your personal level of paranoia.)

NASA today sees about 0.6% of the federal budget: a proportion which has been shrinking steadily since the early 1990s. That funding is divided across a large number of programs and priorities. Not only do they not have clearly stated goals to guide them, they lack the funding to even maintain continuity in the programs (both scientific and engineering) which already exist.

Today's NASA has some superb engineers that I would readily stack up against those from any era in the agency's history. What NASA lacks is funding and leadership. The problem is political, not technical.

Yeah and the political problem goes beyond money. They aren't allowed to take any significant risks because any failure is seen as a major political risk which might get their budget further cut. They also aren't allowed to choose their own designs based on technical merit, they must use SRB's because ATK gives large donations to the campaign of the senators and congressmen from Utah.

Because apparently, the Russians do it better (see video). I also remember there being a stock of leftover engines from the end of the cold war (not sure if it was the NK-33), that exceeded the US theoretical predictions on some maximum engine parameters. So there are still lessons to be learned.

The number after Saturn is not a version number... And if we're going to see another super-heavy lifter, I'd much rather see a Falcon XX or the DIRECT team's Leviathan-140 proposal. The Saturn V was an amazing machine, but we can do things much more cost-efficiently nowadays.

Seems to me that in engineering form tends to follow function. There's only so many practical ways to design an airplane, for instance: tube, wing, or blend; add propulsion, fuel tanks, controls. Then improve materials, fab methods, and play with it - a practical flying wing needed improved controls not available in the early 1900s, for example. http://en.wikipedia.org/wiki/Flying_wing [wikipedia.org]

As to why we went to Luna and quit [downpage], well, that's been lived through, written about, and discussed up the yin-yang. Seems to me it was largely lack of interest and failure of will abetted by the distractions of a bunch of stuff on the front burner. Looking at the past coupla thousand years I get the impression that in the collective, humanity tends to be short-sighted and rather petty. Ditto for many of its members. Which is why, when we do neat things like invent computers, printing press, microwave ovens, nail clippers, and soap, and remove the scourge of polio, smallpox, and such, I applaud and try not to think overmuch about all the things we're _not_ doing. Yeah, I try; not saying it works.

If the space race had continued with the vigour that it did instead of petering out after barely a decade, what could have been achieved and what would have already been achieved by now? Instead we reached the moon, gave a high five then twiddled our thumbs in LEO for the next few decades.

It seems to me like it was a lost opportunity not to maintain the speed of exploration.

bullshit. Agricultural technology is insufficient today for Mars. Restriction enzymes weren't even discovered until the late 1970s. Look at the fungus on Mir and how it attacked with windows. How about the discovery last year that staying in microgravity for months might be permanently bad for eyesight.

The tech simply is not ready. Mir should have kept in orbit, and the human guinea pigs should have been kept in orbit for longer periods of time. Biosphere 2. That should have been done by, or used by NASA mo

If you believe that man's destiny is the stars, then human spaceflight is not pork. They way we're doing it today, it is. What should be done is find some volunteers to make a one-way trip to LEO and keep them there for 50 years. All the science you want.

At the very least, periods of time like 2-5 years. Recovering from that is not much worse than recovering from a 5 year coma, right?

Actually, it was not us that twiddled. USSR stepped things down once we hit the moon. Had they not stepped down, then we would have continued. The problem is that it was expensive to them as well as to us. That is why USSR quit the high spending, followed by Nixon doing the same.

Rapidly? Thor lives on in the first stage of the Delta II. Titan was also a backup program Atlas as the next generation ICBM platform. It wasn't until Saturn and Polaris that the programs really diverged as shrinking warheads meant that the military could transition to SRB's which have all sorts of advantages for a fleet of standby missiles.

But it doesn't live on as a weapon system. In fact, even as the space race was getting going, the liquid fueled IRBM's and ICBM's were starting to be phased out. (Thor deployments ended in 1962.)

It wasn't until Saturn and Polaris that the programs really diverged as shrinking warheads meant that the military could transition to SRB's which have all sorts of advantages for a fleet of standby missiles.

Toxic by-products? What are you smoking? It burns Hydrogen and Oxygen, sure water is corrosive, but I wouldn't call it toxic!

It doesn't burn cleanly, and because they are firing the engine in the atmosphere, there will be byproducts of atmospheric gasses in the exhaust as well. That means HNO3, HCN, NH2, NH3, and who knows what else.

When burning stuff in air you get various nasty nitrogen oxides that turn into nitric acid once they hit the fluid in your lungs. That's with the cleanest flame you can get and that's a major reason why power stations have scrubbers. There's other stuff like a fuel the Russians used to use that is far nastier and even the unburnt liquid will make you sick if it gets on your skin.

So they don't just mix the hydrogen and oxygen in the combustion chamber and light the bitch? They somehow force outside ambient air in there too?

The air doesn't have to be forced in because the flame is forcing itself out.

You idiot. No, I don't say that because I think you are stupid. I don't think you are stupid. I think you could have figured this out on your own. Your objection was absurd and that's your cue that you were looking at it incorrectly. There was only one other way to look at it. This is trivial search space of exactly 2 items. How much easier does it have to be, you one-track minded simpleton?

This test wasn't carried out in space - it was carried out on a test stand on the ground. Air isn't "sucked in" to the combustion chamber, but the flame and exhaust are exposed to the atmosphere, and it is still quite hot at that boundary. Many nitrogen byproducts result. Shooting the exhaust at a waterfall helps to mitigate this.

If it's in space you don't fucking care about the emissions anyway because nobody is there to breath the stuff. What is it about this increasingly common trend here of deliberately pretending to be dumb to "win" an argument after a mistake has been made? Is it due to some bad example from politics or something?

Can ya explain how the nasty stuff from the outside ambient air gets in the combustion chamber to react when it's at 1350 psia and con

I love wanna be intellectuals commenting like they are being funny. I was joking around you ass-hat.

Anyway, if you want, here's something for you to chew on dim whit.

According to what I found online the J-2X looks like it's a step backwards. According to the data on wiki it's bigger, heavier, produces less thrust than the J-2S therefore causing it's thrust to weight ratio to be less than BOTH the J-2 and J-2S.

No, you're not setting the bar too high, but apparently you bar is low enough most won't trip over

According to the data on wiki it's bigger, heavier, produces less thrust than the J-2S therefore causing it's thrust to weight ratio to be less than BOTH the J-2 and J-2S.

Bigger, heavier, and less power-to-weight, however it is more powerful and more efficient. That's all fairly irrelevant. Fuel is cheap, rocket motors are expensive. The original J-2 damned the cost to beat the Ruskies. The RS-25 was recovered with the Shuttle, although that had to be rebuilt after each launch and didn't work out as planned. The J-2X is redesigned using less exotic materials and less complex construction methods. It is supposed to be cheaper, so it is less of a problem to be disposable

In other words, you're looking at under a thousand dollars per second to run the rocket motor, and about half a million for the total burn. Fuel is cheap, the real cost is in the vehicles themselves. That was the whole reason the Shuttle was supposed to be reusable. Had the Shuttle worked as intended, we would be looking at payload costs on the order of $2000/kg rather than the $20000+/kg it saw in practice. The problem with the Shuttle was the costly inspection and refurbishment after each flight.

I must commend you on the the fuel breakdown!
My comment, however, was way beyond the fuel cost as that is negligible. I was thinking more on the legacy costs of overhead, engineering, production, etc.
Given a budget of a couple hundred million and the number of years to create a prototype arrived me to my previous statement.

The article says the J2-X uses liquid oxygen and liquid hydrogen as fuel. Does that imply the byproduct of the J2-X is water vapor? The old Apollo rockets used kerosene. I know NASA used a lot of water to control heat and vibration for shuttle launches and other rocket tests (which is likely what you see in the video)... but is that also the exhaust gas here?

The article says the J2-X uses liquid oxygen and liquid hydrogen as fuel. Does that imply the byproduct of the J2-X is water vapor? The old Apollo rockets used kerosene. I know NASA used a lot of water to control heat and vibration for shuttle launches and other rocket tests (which is likely what you see in the video)... but is that also the exhaust gas here?

Most of the white stuff you see in the video is steam from cooling and sound supression systems. But, in EVERY combustion in air, even if burning pure hydrogen and oxygen, there is some amount of nitrous oxides produced from the nitrogen present in air. This is an inescapable fact of chemistry. But what you're seeing is water vapor.

The amount of NOx produced from a rocket that uses LOX is negligible for the load. The reason is because the actual burn occurred with the O2, not atmosphere. OTH, Jet engines produce a LOT of NOx. It will be many many many times more than a rocket engine. In addition, there is hybrid engines that use nitrous oxide. That will produce a lot of NOx.

The amount of NOx produced from a rocket that uses LOX is negligible for the load. The reason is because the actual burn occurred with the O2, not atmosphere.

Yes, and no. While actual combustion of fuel and oxidizer takes place within the engine, the combustion products are still hot enough to cause reactions between atmospheric nitrogen and oxygen. The real reason they produce negligible amounts is because they spend so little time in the atmosphere. On the gripping hand, a good deal of what they do pro

Hasn't the general consensus been that Russian approach of having numerous cheap launchers better than one big powerful one? Why is money still being wasted on designing a huge launcher that won't be ready for years? Can't NASA just man rate some existing Delta or Atlas launchers, or give SpaceX a little more cash?

Man-rating the Delta and optionally funding a heavy (modular) variant of the Delta and Falcon is the most cost-effective strategy. Unfortunately, it is about keeping the money flowing toward the districts that built the shuttle, not about cost-effective space exploration. Since the space program is a fairly unimportant political issue, congress gets away with it.

Only for 2 more years. Once Falcon Heavy launches, SLS will be killed. The reason is that SLS will only carry 70 tonnes from 2021 until around 2030. Then it was slatted to have 140 tonnes around 2030. And SpaceX will likely have 70 tonnes by 2016, and 140 tonnes by 2021.

Yeah, at this stage if SpaceX loses an F9 or FH, it may finish them. They need to make sure that they get EVERYTHING right.

However, I will say that I remain a fan of KILLING SLS. Instead, I would like to see NASA do a COTS-SHLV. Basically, provide for 2 SHLV of say 140-160 tonnes. NASA will then provide 5 billion and up to 5 years for development. In addition, each launch MUST be below.5B for 2 a year. Then NASA simply agrees to buy 2 launches from each, with an award of an extra launch to the lowest co

The Space Launch System HLV (Heavy Lift Vehicle) as currently designed is fine. However, NASA's human spaceflight program needs a mission.

NASA's proposed SLS-HLV budget of $3 billion per year is much higher than is actually needed to fund an HLV, and appears to be an effort to spend the former Shuttle program funds for political purposes.

NASA needs a deep space mission. From the mission comes the plan; from the plan comes the things necessary for its implementation. NASA needs to fund missions, not things. The mission comes first.

This is exactly right. Apollo was successful because it started with a goal, to land a man on the moon. Kennedy didn't say "Let's build a big Saturn V booster and see what we can do with it later". If he had, it would've almost certainly led to program cancellation later by a Congress asking "What the hell are we spending all this money for?"

The SLS program as it stands now is guaranteed to be cancelled. (but not before many billions are funneled to the well-connected)

NASA today is not the young NASA of the 60's. It's become a bloated bureaucracy.

Pournelle's Iron Law of Bureaucracy:

In any bureaucracy, the people devoted to the benefit of the bureaucracy itself always get in control and those dedicated to the goals the bureaucracy is supposed to accomplish have less and less influence, and sometimes are eliminated entirely.

I should mod you down, but will respond instead. The saturn was started in the 50's. Even the test systems was done in 1960-1962, BEFORE kennedy's speech. Are you surprised? You should not be. Presidents do not like to be made a fool of. Kennedy KNEW that it was possible to go to the moon. More importantly, Kennedy was told beforehand that we were ahead of USSR with rocket tech (for BMs). Where we lacked was human space time and the testing required.

What is important is NOT the construction of a rocket, or even a mission. What is important is having tested designs, manufacturing lines, and having it be CHEAP. From that, you can move forward quickly. For example, it took musk 10 years to build his F9. It will take 2 years to build Falcon Heavy. And if things go well, then Musk will likely build Falcon XX in under 5 years. But the important thing is that Musk will build it CHEAP.

OTH, SLS is simply a continuation of Ares V. Same damn SRBs. Same SME. Same J2X. The difference is that SLS is simply being pushed now with a different name. But we already spent 7 years on Ares. Now to get a TEST launch of a 70 tonne system, it will be another 7 years. The first launch of a human? 10 years and over 20 billion just on the SLS. That does not include the 10 billion that we spent on ares already. Of course, SLS will die in about 2 years when Falcon Heavy works. The FH will take up 54 tonnes at that time. Musk is follow it with Raptor second stage which will give FH 70 tonnes. All by 2016. The real issue is that FH with the raptor will still cost around 1/10 of what the SLS costs to launch. That will lead CONgress to kill the SLS (thank god). Once CONgress will allow NASA to focus on doing BEO tech, THEN we can have missions. LOTS OF MISSIONS. But we need a stable of tested equipment and the ability to do it cheaply and quickly.

I should mod you down, but will respond instead. The saturn was started in the 50's. Even the test systems was done in 1960-1962, BEFORE kennedy's speech.

Not just the Saturn - the Apollo CSM was already in development[1] and was in the process of morphing from being the lunar lander to being the command ship with a separate lunar lander. The (in)famous mode debate over direct ascent vs. EOR vs. LOR was already underway.

Few people realize that direct ascent was even in the race, because by 1962 it was already slipping into third place because it was believed that the booster required would be too large to build and fly within the state-of-the-art. The funny part is that NASA so badly underestimated the size and weight of the spacecraft[2] needed to reach the moon, the Saturn V of 1967 ended up being much larger than the Nova they didn't think could be built in 1962.

Are you surprised? You should not be. Presidents do not like to be made a fool of. Kennedy KNEW that it was possible to go to the moon.

Precisely this. Kennedy and his advisers looked wide and deep at the various technology projects underway in the US at the time, and choose the lunar landing because a) it was In Space (the primary battleground), and b) considerable research and engineering had already been done. The various popular histories of the era even down to today merely repeat the propaganda of the time, that NASA started from more-or-less a standing start.

More importantly, Kennedy was told beforehand that we were ahead of USSR with rocket tech (for BMs). Where we lacked was human space time and the testing required.

Indeed. And once the US got going, the Soviets fell ever further behind, and in some ways they never recovered. Even when it comes to space stations - the Soviets wouldn't beat either the total time accumulated or individual flight lengths until years after Skylab. (Which was essentially a program run with the scraps of the Apollo program.)

[1] Yes, Apollo predates Gemini by a wide margin - and NASA's decision to stick with the existing Apollo (what become the Block I Apollo) would come back to bite them in the butt.

[2] NASA's difficulties with estimating size, weight, budget, and schedule goes back a long ways.

NASA today is not the young NASA of the 60's. It's become a bloated bureaucracy.

As the poster above explains, you're understanding of the history of NASA in the 60's is a bit... deficient. The 'young NASA' of the 60's wasn't what you believe it to be, it was in fact a greatly bloated bureaucracy. I wish I could find the flowchart I once saw listing the process it took to approve the adding of a tool to the flight manifest - it took up three pages of reviews and tests and approvals and oversight committees

How can a single rocket, a tube filled with pork, cost $10 billion? Please explain.

FTFY. Now the answer is obvious.

Dr. Spengler: I'm worried, Arlet. It's getting crowded in there and all my data points point to something big on the horizon.

Winston: What do you mean, big?

Dr. Spengler: Well, let's say this hot dog represents the normal amount of pork for NASA. Based on this morning's test, it would be a hot dog. . . thirty-five feet long, weighing approximately six hundred pounds.

How can a single rocket, a tube filled with fuel, cost $10 billion? Please explain.

The LHC is basically an almost empty tube that doesn't go anywhere. When you consider the difference between the mass of a few protons vs. a full load of rocket fuel, you will see that the $10 billion tube has an amazingly better $/kg payload ratio compared to the $9 billion dollar tube, while only having a ~10% cost difference. Th

In the video there is a gentleman looking through a periscope (1'08") in what I would interpret to be the bunker in case of explosion (with a couple of red covered kill switches?). Then shortly after (1'30"), while the rocket is still burning, it shows a large group of people watching from a relatively short distance away. What gives? Not that I wouldn't mind seeing something like that relatively close!